The strategic landscape for biomedical and biological testing is undergoing a truly disruptive transformation spanning a broad and diverse range of applications from testing for treatment in the physician's office to screening for diseases in the developing world to environmental sensing. The principal drivers for this dramatic development are reducing costs, obtaining faster test results, lowering mortality rates, and reducing morbidity. We will develop and demonstrate a rugged, fluidic-chip-based, multi-parameter flow cytometer that is functionally appropriate for point-of-care (POC) applications and capable of the performance dictated by clinical diagnostic requirements. Detection sensitivity and analyte throughput of the instrument is expected to be comparable or exceeding the specifications of currently available (commercial) high- performance flow cytometers with the added features needed for the POC setting. The enabling technique is termed "spatially modulated fluorescence detection." Relative movement between analyte and a predefined patterned environment generates a time-dependent signal, and correlating the detected signal with the known pattern achieves high discrimination of the particle signal from background noise. Based on this technique a compact, handheld one-color instrument has been demonstrated. The specifications of this prototype clearly indicate that a multi-parameter, high-performance instrument is realizable. In this research project we will conduct laboratory experiments to demonstrate the unique features and realize the ultimate potential of the spatially modulated emission and excitation technique for high-performance POC flow cytometers. We will evaluate its potential for single molecule sensitivity, sub-micron spatial resolution, multi-color detection using a single detector and ultra-high throughout using both parallel and wide analyte channels. Finally we will develop and test a prototype of a compact multi-parameter instrument with high sensitivity and spatial resolution. Declaration of PARC Confidential Information: the data in this proposal shall not be disclosed outside the Government and shall not be duplicated, used, or disclosed in whole or in part for any purpose other than to evaluate the proposal;provided that if a contract is awarded to this offer or as a result of or in connection with the submission of these data, the Government shall have the right to duplicate, use or disclose the data to the extent provided in the contract. This restriction does not limit the Government's right to use information contained in the data if it is obtainable from another source without restriction. The data subject to this restriction are contained in all sheets. PUBLIC HEALTH RELEVANCE: Flow cytometers are indispensable tools for bio-medical diagnostics and treatment. Today these instruments are mainly employed at major, centralized clinical laboratories since compact, robust, and inexpensive instruments of the requisite performance are not available. In this program, we will develop and demonstrate a rugged, fluidic-chip-based, multi-parameter flow cytometer that is functionally appropriate for POC applications and capable of the performance dictated by clinical diagnostic requirements. The enabling technology is termed "spatially modulated fluorescence detection."